1. Field of the Invention
This invention relates to hair treating compositions containing amine oxidation dye precursors such as developers and/or couplers.
2. Statement of the Related Art
Some hair treatment compositions used in hair dyeing contain oxidation dye precursors in a cosmetic carrier. The oxidation dye precursors used are developers and couplers which together form dyes by oxidative coupling with one another under the influence of oxidizing agents or atmospheric oxygen. The cosmetic carriers used for the oxidation dye precursors are creams, emulsions, gels, shampoos, foam aerosols or other preparations suitable for application to the hair.
By virtue of their intensive colors and good fastness properties, oxidation dyes, which are formed by the oxidative coupling of one or more developer components with one another or with one or more coupler components, play a prominent part in the dyeing of hair. The developer components used are normally primary aromatic amines containing additionally a free or substituted hydroxy or amine moiety in the para or ortho position, diaminopyridine derivatives, heterocyclic hydrazone derivatives, 4-aminopyrazolone derivatives and tetraaminopyrimidines. Useful couplers include m-phenylene diamine derivatives, naphthols, resorcinol derivatives and pyrazolones.
Good oxidation dye precursors have to satisfy above all the following requirements: (1) they must form the required shades with sufficient intensity and fastness during the oxidative coupling reaction; (2) they must be readily absorbed by human hair without excessively staining the scalp; and (3) they must be safe to use, above all from the toxicological and dermatological viewpoint.
Although p-phenylene diamine and several of its derivatives have long been known as oxidation dye precursors, it is also known that many of these compounds are neither toxicologically nor dermatologically safe because they show mutagenic and/or allergenic properties. Accordingly, there is considerable commercial interest in oxidation dye precursors which, on the one hand, produce intensive colors characterized by high fastness properties, and which on the other hand, are both toxicologically and dermatologically safe.